Automobile three-way catalytic converter is the most important external purification device installed in automobile exhaust system. It can convert harmful gases such as CO, HC and NOx from automobile exhaust into harmless carbon dioxide, water and nitrogen through oxidation and reduction.
Because this catalytic converter can convert the three main harmful substances in the waste gas into harmless substances at the same time, it is called three ways.
The outside of it is made of two layers of stainless steel sheet. The insulation material —- asbestos fiber felt is installed in the double laminated sheet. The interior is equipped with a purifying agent between mesh partitions. The purifying agent consists of a carrier and a catalyst.
The carrier is generally made of aluminum oxide, and its shape is spherical, polygonal and reticular partition, etc. The purifying agent actually acts as a catalyst, also known as a catalyst. The catalysts are platinum, rhodium and palladium. One of these is sprayed on the carrier to form a purifying agent.
The working principle of the three-way catalytic converter is: when the high temperature automobile exhaust passes through the purification device, the purifying agent in the three-way catalytic converter will enhance the activity of CO, HC and NOx gases, and promote them to carry out certain REDOX chemical reactions. Among them, CO is oxidized to colorless and non-toxic carbon dioxide gas at high temperature. HC compounds are oxidized to water (H20) and carbon dioxide at high temperature; NOx is reduced to nitrogen and oxygen. Three kinds of harmful gas into harmless gas, so that the automobile exhaust can be purified.
unburned mixture should be avoided from entering the catalytic converter. The temperature at which the three-way catalytic converter begins to function is about 200 degrees Celsius, and the best working temperature is between 400 degrees Celsius and 800 degrees Celsius. After more than 1000 degrees Celsius, the noble metal composition of the catalyst itself will also produce chemical changes, so that the effective catalyst composition in the catalytic converter is reduced, so that the catalytic effect is weakened. Therefore, in the process of vehicle use should pay attention to exclude the following situations: one is too long idle idling; Second, the ignition time is too late; Three is the individual cylinder fire does not work; Fourth, it is difficult to start; Fifth, the mixture is too thick; Six is the engine oil burning, seven is the oxygen sensor failure; Eight is the water temperature caused by poor heat dissipation is too high. The same ternary catalytic converter, different models, the engine commonly used working range is different.
